Backstage at the Ellen show, the YouTube sensation revealed he couldn’t even name ONE Madonna song — let alone know who she is!

Thanks to little Greyson Michael Chance, we’re starting to feel REALLY old. Before taping his segment on the Ellen Show May 25, ‘Baby Bieber’ admitted to HollywoodLife.com’s insider he doesn’t have any idea who the Queen of Pop is — even though they share the same manager!